The recording/playing apparatus such as a VTR will be very convenient if it can record or reproduce signals defined according to a plurality of different television standards. More particularly, the VTR should desirably be capable of recording or reproducing signals used in the television systems (TV system) adopted in all countries, respectively, over the world such as Japan, USA and Europe. The HDTV (high-definition television) system was first developed in Japan to display a higher-definition picture than the conventional TV system. In Japan, the HDTV system is called “Hi-Vision” system and defined as using 1125 scanning lines and a field frequency of 60 Hz. On the other hand, the HDTV systems in the Europe and USA are different in various aspects from the Hi-Vision system in Japan. For example, the field frequency in the European HDTV system is 50 Hz.
The TV system varies among the countries as above, and hence TV equipment and materials used in a country for program production and broadcasting are thus inevitably different from those used in another country. Namely, the TV equipment and materials for production and broadcasting have to developed and manufactured for conformity with the different TV systems, respectively, which will lead to large costs of program production and broadcasting. Also, for playing a software produced in compliance with a TV system, a VTR conforming to that TV system has to be used and TV signals have to be converted in format by a separate format converter for re-recording to the VTR, which will also lead to increased labor and cost.
The VTR is one of the essential equipment and materials for producing and broadcasting a program. Generally, since the broadcasting VTRs are at heavy prices, so it is desired that a tape transport, signal processing circuit, tape cassette and the like are usable in common between VTRs conforming to different HDTV systems. This will lead to a reduction of the equipment costs and running costs and also be very profitable to the users. Also, if a tape having a program recorded therein in compliance with a plurality of different TV systems can be played in the same VTR, the program can advantageously be exchanged among the countries adopting the different TV systems, respectively, at low costs.
However, the conventional magnetic recording/playing apparatuses like a VTR do not incorporate any recording/playing mechanism common to such different HDTV systems and thus cannot record and reproduce any high-definition video data and audio data produced in compliance with the HDTV systems. For an apparatus capable of recording and reproducing signals different in field frequency from each other, a processor was required which formats each of the signals of different field frequencies for the signals to be dealt with in the apparatus. Assume here for example that there are two apparatuses one of which accommodates signals having a field frequency of 60 fields/sec, audio input/output sampling frequency of 48 kHz and a number of bits per sample of 24 and the other accommodates signals of 50 fields/sec in field frequency, 48 kHz in audio input/output sampling frequency and of 24 in number of bits per sample. It should be noted that the apparatus for data of 60 fields/sec in field frequency will also be referred to as “60-fields/sec apparatus or VTR” hereunder and the apparatus for data of 50 fields in field frequency will also be referred to as “50-fields/sec apparatus or VTR” hereunder. In this case, the audio format for the 60-kHz apparatus should be 800 samples/field×24 bits/sample, and that for the 50-kHz apparatus be 960 samples/field×24 bits/sample. Between these signals, there is a large difference in total number of bits per field. Namely, the total number of bits per field of the signal having the field frequency of 60 fields/sec is 800×24(=19200) while that of the signal of 50 fields/sec is 960×24(=23040). Therefore, the apparatuses for recording and reproducing signals of different field frequencies are inevitably quite different in format from each other.
Also, the video frame varies between field frequencies. Therefore, an apparatus for a signal of one field frequency was unavoidably quite different in signal format from an apparatus for a signal of another field frequency.